The overall goal of the project is to test whether previously demonstrated differences in heart rate (HR) and variability (HRV) in the fetus associated with maternal zinc supplementation result in differences in cognitive and physiologic function during childhood as assessed at 4 years of age. We propose to evaluate the cognitive and physiologic functioning, general health and nutritional status of 155 Peruvian children from a cohort of 195 fetuses whose neural development we studied during pregnancy. To assess cognitive and social-emotional functioning, we will utilize a protocol developed at NICHD and already adapted for studying multiple facets of cognitive and social functioning in 4-year old Latin American children. Specifically, we will assess representational ability, language and number skills, mechanical ability, problem solving and intelligence, as well as adjustment and adaptive behavior through questionnaires administered to the mother. To characterize physiologic function, we will monitor HR and movements in these children at rest and during cognitive tasks. In addition, we will conduct a general medical exam and assess overall nutriture (anthropometric status, usual dietary intake, and current micronutrient status). Relevant history on postnatal morbidity, growth and development will be abstracted from clinic records. Because maternal and environmental factors influence child development, we plan to assess aspects of the mother (maternal verbal intelligence, maternal-child interaction, stresses, social support in parenting, anthropometric and mineral status) and of the home environment (socioeconomic status, family composition, child care, employment, HOME inventory). This study presents a unique opportunity to examine the fetal origins of individual differences in cognitive function, and the neurobehavioral basis for these differences. The findings will open new avenues for investigating the influence of gestational zinc status on the ontogeny of human neurobehavioral development, and inform public health recommendations for optimal zinc intakes during pregnancy.